A model for a Regge trajectory compatible with the threshold behavior required by unitarity and asymptotics in agreement with analyticity constraints is given in explicit form. The model is confronted in the time-like region with widths and masses of the mesonic resonances and, in the space-like region, the $\rho$ trajectory is compared with predictions derived from $\pi-N$ charge-exchange reaction. Breaking of the exchange degeneracy is studied in the model and its effect on both the masses and widths is determined.Comment: 17 pages, 3 figure

J= photoproduction is studied in the framework of the analytic S-matrix theory. The differential and integrated elastic cross sections for J= photoproduction are calculated from a dual amplitude with Mandelstam analyticity. It is argued that, at low energies, the background, which is the low-energy equivalent of the high-energy diffraction, replaces the Pomeron exchange. The onset of the high-energy Pomeron dominance is estimated from the fits to the data.

A factorized Regge-pole model for deeply virtual Compton scattering is suggested. The use of an effective logarithmic Regge-Pomeron trajectory provides for the description of both "soft" (small |t|) and "hard" (large |t|) dynamics. The model contains explicitly the photoproduction and the DIS limits and fits the existing HERA data on deeply virtual Compton scattering.

Ultrahigh energy (E Ͼ10 8 GeV͒ neutrino-nucleon total cross sections N are estimated from a soft nonperturbative model complemented by an approximate QCD evolution, explicitly calculated. The resulting asymptotic energy behavior of the neutrino-nucleon charged-current total cross section is derived analytically, and predictions concerning the observation of ultrahigh energy neutrinos in future experiments are presented.